Cooled detecting device

Abstract

A detection device for infrared radiation has a detection circuit of infrared radiation equipped with at least one photodetector. A readout circuit is electrically connected to the detection circuit, and is configured to process the signal emitted by the detection circuit. A Joule-Thomson cooler cools a cold table thermally and mechanically connected to the detection circuit and the readout circuit. The cold table including an internal cavity supplied with gaseous mixture. A relief port of the gas mixture is arranged at an input in the internal cavity. An output of the compressor feeds the relief port in a gaseous mixture. The input of the compressor receives the relaxed gaseous mixture from an output of the internal cavity.

The invention claimed is: 
     
       1. A device for detecting infrared radiation, the device comprising:
 a detection circuit configured to detect the infrared radiation, the detection circuit being provided with at least one photodetector; 
 a readout circuit electrically connected to the detection circuit and being configured to process an electrical signal transmitted by the detection circuit; and 
 a Joule-Thomson cooler including:
 a cold table thermally and mechanically connected to the detection circuit and the readout circuit, the cold table having an internal cavity; 
 a relief port arranged at an input of the internal cavity, the relief port being configured to relax a gas and cool the cold table by a Joule-Thomson effect; and 
 a compressor with an outlet supplying the relief port with gas and an input receiving the relaxed gas from an output of the internal cavity, wherein 
 
 an inner wall of the internal cavity is textured in the vicinity of the device to form an evaporator, the evaporator being in thermal contact with the device. 
 
     
     
       2. The device according to  claim 1 , further comprising an exchanger configured to cool the gas at the outlet of the compressor by means of the relaxed gas at the output of the internal cavity. 
     
     
       3. The device according to  claim 2 , wherein the exchanger is a countercurrent exchanger. 
     
     
       4. The device according to  claim 1 , wherein the compressor is configured to generate a pressure gradient between 2 and 15 bar. 
     
     
       5. The device according to  claim 1 , wherein the detection device is devoid of a pre-cooling module of the gas. 
     
     
       6. The device according to  claim 1 , wherein the detection circuit and the readout circuit are fixed onto the cold table. 
     
     
       7. A cooling process for detecting infrared radiation, the cooling process comprising:
 providing a detection device configured to detect infrared radiation including:
 a detection circuit configured to detect the infrared radiation, the detection circuit being provided with at least one photodetector, 
 a readout circuit electrically connected to the detection circuit and being configured to process an electrical signal transmitted by the detection circuit, and 
 a Joule-Thomson cooler including:
 a cold table thermally and mechanically connected to the detection circuit and the readout circuit, the cold table having an internal cavity, 
 a relief port arranged at an input of the internal cavity, the relief port being configured to relax a gas and cool the cold table by a Joule-Thomson effect, and 
 a compressor with an outlet supplying the relief port with gas and an input receiving the relaxed gas from an output of the internal cavity, wherein 
 
 
 the gas is a gaseous mixture containing at least one gas selected among ethane, isobutane, methane, krypton, propane, pentane, ethylene, butane, and 
 an inner wall of the internal cavity is textured in the vicinity of the detection device to form an evaporator, the evaporator being in thermal contact with the detection device. 
 
     
     
       8. The cooling process according to  claim 7 , wherein the gaseous mixture contains at least one non liquefiable gas at the operating temperature of the cooler in order to have a gaseous phase upstream and downstream of the compressor. 
     
     
       9. The cooling process according to  claim 7 , wherein the gaseous mixture contains at least one additive of hydrofluoroether type. 
     
     
       10. The device according to  claim 6 , wherein the detection circuit is fixed to the readout circuit and the readout circuit separated the detection circuit from the cold table.